Feasibility of mesorectal vascular invasion in predicting early distant metastasis in patients with stage T3 rectal cancer based on rectal MRI.

Abstract

To evaluate the feasibility of mesorectal vascular invasion (MVI) in predicting early distant metastasis developed within 1 year of diagnosis of T3 rectal cancer using magnetic resonance imaging (MRI) METHODS: Sixty-five patients with T3 rectal cancer (early metastasis, n = 28; non-metastasis, n = 37) were enrolled in this study. Early distant metastases developed in 28 patients (liver, n = 15; lung, n = 9; both, n = 4). Logistic regression was used to determine the independent predictors for early distant metastasis. In univariate analysis, tumour location, carcinoembryonic antigen (CEA), lymphovascular invasion (LVI), MRI-detected MVI, and mesorectal fat infiltration (MFI) (odds ratio [OR], 4.533, 9.583, 5.539, 27.046, and 5.539, respectively) were associated with early distant metastasis. Multivariate analysis demonstrated that MVI (OR, 29.949; P < 0.002) and LVI (OR, 6.684; P = 0.033) were independent factors for early distant metastasis. Specificity and positive predictive value (PPV) of MVI (94.59%, and 89.47%, respectively) were significantly higher than those of LVI (64.86%, and 61.76%), but sensitivity and negative predictive value were not significantly different between MVI (60.71%, and 76.09%) and LVI (75.00%, and 77.42%). While sensitivity of MRI-detected MVI was equal to that of CEA in predicting early distant metastasis from T3 rectal cancer, specificity and PPV may be improved by assessing MVI. • Mesorectal vascular invasion (MVI) may be a radiologic prognostic factor for rectal cancer. • Specificity of MVI was higher than lymphovascular invasion in predicting early metastasis. • Mesorectal vascular invasion may be a better predictor for early distant metastasis.